A Laboratory Experiment Using Molecular Models for an Introductory Chemistry ClassShahrokh GhaffariPresents a new approach to using molecular models in teaching general chemistry concepts. Students construct molecular models and use them to balance simple chemical equations, demonstrate the law of conservation of mass, and discover the relationship between the mole and molecules and atoms.Ghaffari, Shahrokh. J. Chem. Educ.2006, 83, 1182.

Molecular Modeling |

Stoichiometry |

Student-Centered Learning

Interactive Demonstrations for Mole Ratios and Limiting ReagentsCrystal Wood and Bryan BreyfogleThe objective of this study was to develop interactive lecture demonstrations based on conceptual-change learning theory. Experimental instruction was designed for an introductory chemistry course for nonmajors to address misconceptions related to mole ratios and limiting reagentsWood, Crystal; Breyfogle, Bryan. J. Chem. Educ.2006, 83, 741.

Learning Theories |

Reactions |

Stoichiometry |

Student-Centered Learning

Procedure for Decomposing a Redox Reaction into Half-ReactionsIlie Fishtik and Ladislav H. BerkaThe principle of stoichiometric uniqueness provides a simple algorithm to check whether a simple redox reaction may be uniquely decomposed into half-reactions in a single way. For complex redox reactions the approach permits a complete enumeration of a finite and unique number of ways a redox reaction may be decomposed into half-reactions. Several examples are given. Fishtik, Ilie; Berka, Ladislav H. J. Chem. Educ.2005, 82, 553.

Stoichiometry |

Equilibrium |

Electrochemistry |

Oxidation / Reduction |

Reactions |

Thermodynamics

Evaluating Students' Conceptual Understanding of Balanced Equations and Stoichiometric Ratios Using a Particulate DrawingMichael J. SangerA total of 156 students were asked to provide free-response balanced chemical equations for a classic multiple-choice particulate-drawing question first used by Nurrenbern and Pickering. The balanced equations and the number of students providing each equation are reported in this study. The most common student errors included a confusion between the concepts of subscripts and coefficients and including unreacted chemical species in the equation. Sanger, Michael J. J. Chem. Educ.2005, 82, 131.

Stoichiometry |

Kinetic-Molecular Theory

Using Knowledge Space Theory To Assess Student Understanding of StoichiometryRamesh D. Arasasingham, Mare Taagepera, Frank Potter, and Stacy LonjersUsing the concept of stoichiometry we examined the ability of beginning college chemistry students to make connections among the molecular, symbolic, and graphical representations of chemical phenomena, as well as to conceptualize, visualize, and solve numerical problems. Students took a test designed to follow conceptual development; we then analyzed student responses and the connectivities of their responses, or the cognitive organization of the material or thinking patterns, applying knowledge space theory (KST). The results reveal that the students' logical frameworks of conceptual understanding were very weak and lacked an integrated understanding of some of the fundamental aspects of chemical reactivity. Arasasingham, Ramesh D.; Taagepera, Mare; Potter, Frank; Lonjers, Stacy. J. Chem. Educ.2004, 81, 1517.

Learning Theories |

Stoichiometry |

Constructivism

The Decomposition of Zinc Carbonate: Using Stoichiometry To Choose between Chemical FormulasStephen DeMeoTo determine which formula corresponds to a bottle labeled "zinc carbonate", students perform qualitative tests on three of zinc carbonate's decomposition products: zinc oxide, carbon dioxide, and water. Next students make quantitative measurements to find molar ratios and compare them with the coefficients of the balanced chemical equations. This allows the correct formula of zinc carbonate to be deduced. DeMeo, Stephen. J. Chem. Educ.2004, 81, 119.

Analysis of an Oxygen Bleach: A Redox Titration LabChristine L. Copper and Edward KoubekStudents balance the reaction of H2O2 and MnO4 in two different ways (one assuming that H2O2 is the oxygen source and a second assuming that MnO4 is the oxygen source), determine which of these balanced equations has the correct stoichiometry by titrating a standard H2O2 solution with KMnO4, and use the correct balanced equation to determine the mass percent of H2O2 in a commercially available bleach solution. Copper, Christine L.; Koubek, Edward. J. Chem. Educ.2001, 78, 652.

Quantitative Analysis |

Oxidation / Reduction |

Stoichiometry |

Titration / Volumetric Analysis |

Consumer Chemistry

Using Games To Teach Chemistry. 2. CHeMoVEr Board GameJeanne V. RussellA board game similar to Sorry or Parcheesi was developed. Students must answer chemistry questions correctly to move their game piece around the board. Card decks contain questions on balancing equations, identifying the types of equations, and predicting products from given reactants. Russell, Jeanne V. J. Chem. Educ.1999, 76, 487.

Redox Balancing without PuzzlingMarten J. ten HoorOnce it has been established by experiment that the given reactants can indeed be converted into the given products, chemistry has done its job. Balancing the equation of the reaction is a matter of mathematics only. ten Hoor, Marten J. J. Chem. Educ.1997, 74, 1367.

Stoichiometry |

Oxidation / Reduction

A New and General Method for Balancing Chemical Equations by InspectionsChunshi GuoAny chemical equation, no matter how complicated, can be balanced by inspection. In fact, inspection is often the quickest and easiest way to balance complex equation. The method described here involves the use of "linked sets". It does not require the use of oxidation numbers of the splitting of equations into "half reactions". It can be used to balance all kinds of chemical equations, including ionic equations.Guo, Chunshi. J. Chem. Educ.1997, 74, 1365.

Stoichiometry

Balancing Chemical Equations by InspectionZoltán TóthThe paper shows that the balancing chemical equations by inspection is not a trial-and-error process, because a systematic procedure for the balancing simple and more complicated chemical equations without oxidation numbers or equations with several unknowns can be suggested. The proposed method is suitable for balancing all the chemical equations, including ionic equations, which have single unique solution. Toth, Zoltan. J. Chem. Educ.1997, 74, 1363.

Stoichiometry

On Balancing Chemical Equations: Past and PresentWilliam C. HerndonThe main purposes of this paper are to give a listing of selected papers on balancing chemical equations that may be useful to chemistry teachers and potential authors as background material, and to provide some comparisons of methods. The selection criteria for the references were deliberately broad, in order to include a wide variety of topics and seminal historical citations, and the references are annotated to increase their usefulness.Herndon, William C. J. Chem. Educ.1997, 74, 1359.

An Analysis of the Algebraic Method for Balancing Chemical ReactionsJohn A. OlsonA new aspect of this treatment is the mathematical formulation of a third condition involving a balance between oxidation and reduction. The treatment begins with the three general conditions that a balanced chemical reaction must satisfy. These conditions are then expressed in mathematical form that enables the stoichiometric coefficients to be determined.Olson, John A. . J. Chem. Educ.1997, 74, 538.

How Do I Balance Thee? ... Let Me Count the Ways!Lawrence A. FergusonThe author suggests that this would be a good equation for students to try to balance by trial and error because it has two different sets of coefficients that are not multiples of each other. Ferguson, Lawrence A. J. Chem. Educ.1996, 73, 1129.

Balancing a chemical equation: What does it mean?Filgueiras, Carlos AStudents were puzzled by the idea that one chemical equation could be balanced in several different ways. This led to a fruitful discussion on how exact a science chemistry really is.Filgueiras, Carlos A J. Chem. Educ.1992, 69, 276.

Stoichiometry |

Oxidation / Reduction

Chemical equations are actually matrix equationsAlberty, Robert A.Chemists tend to think that chemical equations are unique to chemistry and they are not used to thinking of chemical equations as the mathematical equations they in fact are. The objective of this paper is to illustrate the mathematical significance of chemical equations.Alberty, Robert A. J. Chem. Educ.1991, 68, 984.

Stoichiometry |

Chemometrics

Nitric oxide leftoversHornack, Fred M.This example shows that a stoichiometric problem can be solved in a number of different but equally valid ways.Hornack, Fred M. J. Chem. Educ.1990, 67, 496.

A question of basic chemical literacy? Missen, Ronald W.; Smith, William R.The ability to read and write clearly in chemical-equation terms is not as well developed as it should be. The purpose of this "Provocative Opinion" is to draw attention to this problem, and to suggest specific remedies for its solution.Missen, Ronald W.; Smith, William R. J. Chem. Educ.1989, 66, 217.

A new method to balance chemical equationsGarcia, ArcesioA simple method, applicable to any kind of reaction, that does not require the knowledge of oxidation numbers.Garcia, Arcesio J. Chem. Educ.1987, 64, 247.

Stoichiometry |

Oxidation State |

Reactions

The chemistry tutor (Rinehart, F.P.)Watkins, Stanley R.; Krugh, William D.Two reviews of a two-disk package that is designed to help students master the essential skills of equation balancing, stoichiometric,and limiting reagents calculations.Watkins, Stanley R.; Krugh, William D. J. Chem. Educ.1986, 63, A206.

What can we do about Sue: A case study of competenceHerron, J. Dudley; Greenbowe, Thomas J.A case study of a "successful" student who is representative of other successful students that are not prepared to solve novel problems.Herron, J. Dudley; Greenbowe, Thomas J. J. Chem. Educ.1986, 63, 528.

Pressure and the exploding beverage container Perkins, Robert R.The question in this article is an extension of exploding pop bottles to illustrate the balancing of a chemical equation, enthalpy, stoichiometry, and vapor pressure calculations, and the use of the Ideal Gas Equation. The question is aimed at the first-year level student.Perkins, Robert R. J. Chem. Educ.1981, 58, 363.

The chemical equation. Part I: Simple reactionsKolb, DorisA chemical equation is often misunderstood by students as an "equation" that is used in chemistry. However, a more accurate description is that it is a concise statement describing a chemical reaction expressed in chemical symbolism.Kolb, Doris J. Chem. Educ.1978, 55, 184.

Material balances and redox equationsBennett, George W.It is the purpose of this paper to remind teachers of a third method of balancing redox equations that does not depend on rule-of-thumb empiricism but relies on the conservation of matter.Bennett, George W. J. Chem. Educ.1954, 31, 324.

Stoichiometry |

Oxidation / Reduction |

Oxidation State

Otis Coe Johnson and redox equationsBennett, George W.It is the purpose of this paper to point out what is basic verity and what is empiricism in Johnson's method for balancing oxidation-reduction equations.Bennett, George W. J. Chem. Educ.1954, 31, 157.